The Ceph Storage Cluster runs with authentication turned on by default.
You should have a file containing the secret key (i.e., not the keyring
itself). To obtain the secret key for a particular user, perform the
following procedure:

Identify a key for a user within a keyring file. For example:

catceph.client.admin.keyring

Copy the key of the user who will be using the mounted Ceph FS filesystem.
It should look something like this:

[client.admin]key=AQCj2YpRiAe6CxAA7/ETt7Hcl9IyxyYciVs47w==

Open a text editor.

Paste the key into an empty file. It should look something like this:

AQCj2YpRiAe6CxAA7/ETt7Hcl9IyxyYciVs47w==

Save the file with the user name as an attribute
(e.g., admin.secret).

Ensure the file permissions are appropriate for the user, but not
visible to other users.